Astronaut training requires a diverse range of training techniques – classroom work, simulation, and practical exercises.

Flight simulation allows an astronaut candidate to previsualize an entire mission. With motion-based simulators, he can even experience some of the movement. Thanks to Moore’s Law, flight simulators are becoming better and cheaper all the time.

Simulators have certain limitations, however, which will never be overcome by advances in technology. A crew member in a simulator, however sophisticated, knows he is in a simulator. Simulation cannot reproduce the human factors – the excitement, stress, and risk – of actual spaceflight.

The United States Rocket Academy uses aircraft to reproduce some of those factors which are absent in the simulator. This video shows a typical training flight using aerobatic airplanes, with citizen-astronaut candidates Maureen Adams and Lt. Col. Steve Heck (USAF-ret.).

Written by Astro1 on June 30th, 2012 , Citizens in Space, Space Medicine and Safety

Dr. Neil deGrasse Tyson is an astrophysicist who has become one of the best informal educators in the nation – possibly the best, when it comes to space science.

That expertise does not necessarily carry  over into other fields, such as politics, however. Dr. Tyson’s call for doubling the size of NASA’s budget to 1% of Federal spending, which inspired a public petition, was naive at best.

Making “percent of Federal spending” a figure of merit for any agency, including NASA, is a flawed idea. Space programs should be funded (or not funded) on their own merits, on the basis of an entitlement.

No other Federal program is funded on a “percentage” basis. To ask that NASA be funded on such a basis suggests that its budget level cannot be supported on its merits, which is a dangerous thing for NASA’s supporters to suggest. It would be even more dangerous if the idea of percentage entitlements caught on. There are probably 200 special-interest groups that would suggest their program should have 1% of the Federal budget, most of them with far more political clout than NASA. There’s no way NASA would come out on top.

That would be true even if times were good economically, but times are not good. To suggest doubling the size of NASA’s budget in today’s economic climate suggests that Dr. Tyson is out of touch politically.

It wouldn’t be the first time he has appeared out of touch. In 2004, Dr. Tyson was one of the members of the Aldridge Commission on space policy, which declared that human spaceflight would “remain the providence [sic] of government” – in a report issued shortly after SpaceShip One became the first private craft to be piloted into space.

In fairness, Dr. Tyson may not have fully read the entire report and realized what he was signing. Others apparently did not. Dr. Paul Spudis, a lunar scientist and another member of the Commission, has  defended that statement, saying it only applied to human spaceflight beyond Earth orbit. The text of the written document  does not support that claim, however.

A more fundamental question might be why astrophysicists and planetary scientists are asked to decide policy on human spaceflight. This seems to come from the popular misconception that spacecraft are developed by “rocket scientists.” But, of course, spacecraft are not developed by scientists. They are developed by engineers. We don’t expect geologists to design trucks or be experts on trucking policy. We don’t expect oceanographers to know how to design ships or run a shipping line. And we don’t ask meteorologists to design a jet fighter or run the Air Force. Why, then, do we expect astronomers and planetary scientists to be experts on what sort of human spaceflight capabilities the United States should develop?

Written by Astro1 on June 29th, 2012 , Space Exploration (General)

A private foundation is taking another step to discover asteroids which pose a potential threat to Earth.

The B612 Foundation, founded by astronauts Rusty Schweickert and Ed Lu, has announced the Sentinel mission, a solar orbiting infrared telescope designed to discover and catalog 90 percent of the asteroids larger than 140 meters in Earth’s region of the solar system. The mission should also discover a significant number of smaller asteroids down to a diameter of 30 meters. Sentinel will be launched into what the B612 Foundation calls a Venus-like orbit, which significantly improves the efficiency of asteroid discovery during its 5.5 year mission.

The Sentinel telescope is innovative in a number of ways. First, is that it will be the first privately financed mission to deep space. Second, it will be a smart spacecraft. Data will be processed onboard by asteroid-detection software. This minimizes the amount of data that needs to be downloaded back to Earth. Onboard processing will be important for future low-cost deep-space missions in order to reduce network operating costs. Instead of being in constant contact with Earth, Sentinel will report in once a week.

Read the rest of this entry »

Written by Astro1 on June 28th, 2012 , Innovation, Planetary Defense

The Apple iPhone, which was launched five years ago, has generated $150 billion in total revenue for Apple, according to a report by Strategiv Analytics as reported by Appleinsider.com.

That figure may not surprise you. By now, most people are used to hearing superlatives about Apple’s iPhone business.

The success of the iPhone has been so spectacular that most people forget that it was not always assured. In fact, many business analysts did not believe Apple could succeed in the smartphone market. Microsoft President Steve Balmer famously declared, on stage at a public conference, that it was “impossible for Apple to get any significant market share.”

People were especially skeptical about the iPhone’s radical touchscreen design. Touchscreens existed long before the iPhone, but they simply didn’t work very well. The iPhone completely redefined what a smartphone could do, and what users expected from a smartphone.

That’s innovation, as practiced in Silicon Valley. Then we have human spaceflight, where innovation is almost a dirty word.

Read the rest of this entry »

Written by Astro1 on June 28th, 2012 , Innovation, Space Exploration (General)

Suborbital spacecraft may play an important role in training astronauts for orbital and deep-space missions.

Today, US astronauts (and their foreign counterparts) receive no training on rocket-powered vehicles prior to their first orbital flight. Whether they are pilots or payload operators, they are “thrown into the deep end of the pool” on their first space mission. Space agencies attempt to compensate, through extensive ground-based training and simulation, but the step up from ground-based training to actual flight is still enormous. Then, completing their mission, astronauts face a gap of many months or years before their next flight. Military and airline pilots have to meet regular “currency requirements,” but astronauts have no way to stay current in rocket-powered vehicles.

NASA has recognized the potential value of suborbital spacecraft for astronaut training. In 2008, NASA Administrator Mike Griffin said, “We could use commercial suborbital human transportation for early training and qualification of astronauts. If I could buy a seat to suborbital flight for a few hundred thousand dollars, why wouldn’t we have all of our new astros make their first flight in such a manner?” NASA never followed through on proposed studies of such training, however, perhaps because of budget overruns in other areas.

Commercial space companies are interested, however. XCOR Aerospace and Excalibur Almaz recently signed a memorandum of understanding that would open the door for XCOR to provide training for Excalibur Almaz astronauts using the Lynx spacecraft. If the idea catches on, suborbital spaceflight may become a standard part of the training toolkit for all future astronauts.

Such training could provide additional impetus for the development of a commercial spaceports near national space centers. It could be a particular boon to Texas. There has already been talk of establishing a suborbital spaceport at Ellington Airport, adjacent to NASA’s Johnson Space Center. Commercial suborbital spacecraft would be a useful supplement to the fleet of T-38 Talon jet trainers which NASA already has based at Ellington.

Excalibur Almaz Space Expeditions

Excalibur Almaz is marketing a commercial space capsule called the RRV, or Reusable Reentry Vehicle, based on the TKS capsule developed by the Soviet Union during the Cold War. The TKS capsule was intended for use with the Almaz (military Salyut) space station. It was tested in an unmanned configuration, but the Almaz program was cancelled before manned flights of the capsule were conducted.

Excalibur Almaz RRV (Reusable Reentry Vehicle) space capsule

Read the rest of this entry »

Written by Astro1 on June 27th, 2012 , Excalibur Almaz, Innovation, Space History, XCOR Aerospace

China has once again amazed the world. It appears the world is easily amazed.

First, there was the exaggerated praise heaped on China for successfully docking with a space station (duplicating a feat the United States and Soviet Union accomplished decades ago).

Now, China has astounded journalists with a record-breaking submersible dive to the bottom of the Mariana Trench.

Except, the dive didn’t break any records. The reported depth (7,015 meters) is only about two-thirds of the depth James Cameron reached in his self-funded dive a few weeks ago (which is the greatest depth any human being can reach). It’s also two-thirds of the depth which Jacques Picard and US Navy Lieutenant Don Walsh reached in 1960. Apparently, the Chinese weren’t diving the deepest part of the trench.

Still, the fact that the populous largest nation almost managed to equal a feat accomplished by a private citizen is considered a sign of “global leadership.” (Does that make James Cameron a global leader?)

This lack of perspective is embarrassing. If this continues, we may find ourselves about how China has made history by landing on the Moon – about a decade or so after US commercial space companies and 60 years after Apollo. 

Written by Astro1 on June 26th, 2012 , Space Exploration (General)

This weekend, Citizens in Space participated at Maker Faire in Kansas City. In just two days, we met and interacted with more new people than most space activist groups attract with an entire year of conferences and expensive parties.

Why is that?

Read the rest of this entry »

Written by Astro1 on June 24th, 2012 , Citizens in Space

An article by Dr. Morris Jones takes issue with China referring to Tiangong 1 as a laboratory, rather than a space station.

At first blush, that criticism seems trite. The Chinese government is entitled to call its space station a laboratory if it wants to. Others may or may not choose to go along. (We have called Tiangong 1 a space station and will continue to do so.)

This does inspire us to wonder, though, why does China eschew the use of the term “space station”? Since the Chinese space program seems to be motivated primarily by prestige, we would logically expect Tiangong 1 to be described in the most grandiose and prestigious terms possible.

Has the political fiasco of the International Space Station program soured the term? Will space-station developers have to use euphemisms like “laboratory” in the future?

Perhaps we’re reading too much into this. Or perhaps not.

Written by Astro1 on June 23rd, 2012 , Space Stations

In the early 1980’s, NASA pursued parallel space-station studies. Marshall Space Flight Center favored a series of space platforms, initially unmanned but human-tended by regular Shuttle missions, that would evolve toward a permanently manned platform. (The Carter Administration had banned all discussion of space stations, so euphemisms were necessary.) Unmanned platforms would be located in both polar and low-inclination orbits. (This was prior to the Challenger accident, and NASA still expected to operate a West Coast launch site for Shuttle launches to polar orbit.) The manned platform would be located in the low-inclination orbit. The platforms would be devoted to space science, primarily microgravity and astronomy for the low-inclination platforms, Earth observation in polar orbit.

Johnson Space Center, on the other hand, had minimal interest in science. It favored a concept called the Space Operations Center, which would be dedicated to the support of in-space operations.

20120621-235328.jpg

Read the rest of this entry »

Written by Astro1 on June 23rd, 2012 , Space History

If there is an international space race (something we’re not at all certain of), the European Space Agency just made a strategic move to pass by approving construction of the Euclid space telescope.

Never mind the recent hype about China and thr first crewing of the Tiangong space station. Space races are mostly about public relations. Even Apollo was about PR. (You didn’t think landing Neil Armstrong on the Moon really affected the Cold War balance of power, did you?) The public doesn’t  care much about the International Space Station, and there’s no reason to think the China’s (smaller, less capable) space station will generate any long-term interest, either. Ask most people what NASA’s greatest accomplishment is, and they’re more likely to say “Hubble” than “ISS.”

Hubble will be retired in a few years, however, and NASA has no plans for a replacement. No, we’re not forgetting JWST. The James Webb Space Telescope has been billed as a replacement for Hubble, but it isn’t. JWST is an infrared telescope; it won’t produce the sort of visible-light images that made Hubble so immensely popular. Once JWST is in orbit and the public realizes that fact, buyer’s remorse is likely to set in. We’re not sure NASA though this one through.

NASA recently took delivery of two Hubble-class telescopes originally built for the National Reconnaissance Office. Unfortunately,  it can’t afford to launch either one of them due to JWST overruns and  “monster rocket” expenditures eating up the NASA budget.

So, ESA’s approval of the Euclid space telescope is a timely move. With a 576-megapixel visible camera and optical resolution comparable to Hubble, Euclid will be positioned to take over Hubble’s role as the public’s favorite telescope. In government space programs, image is everything, and there’s little doubt Euclid will produce stunning images.

Still, it’s a bit disappointing to see a government space agency investing a billion dollars in a conventional Hubble replacement instead of pioneering new technology like optical interferometry. To misquote an old saying, give a man a telescope, and he will observe for a day; develop the technology to build better, cheaper telescopes, and he will observe for the rest of all time.

That’s one of the reasons Planetary Resources’ planned Arkyd-100 telescope constellation is so interesting. A large of number of relatively modest, but low-cost, space telescopes could be a game changer. A recent blog post from the company suggests Arkyd-100 may give amateur and professional astronomers the chance to take a directed picture of an object of their choice for just $100, compared to over $10,000 for other space telescopes.

Written by Astro1 on June 21st, 2012 , Astronomy, Innovation, Planetary Resources

Eight years ago today, Mike Melvill flew SpaceShip One to an altitude of 100.124 kilometers, becoming the first pilot to qualify for the FAA’s commercial astronaut wings.

In centuries to come, June 21, 2004 will be remembered as the start of the real Space Age – the era when humans finally began to open up space in large numbers.

Today, however, it will pass largely unnoticed. The so-called “New Space” groups have their big parties to celebrate the launch of Yuri Gagarin and every Apollo landing. (There’s not much new about in “New” Space.)

We won’t be celebrating today, either. It’s been eight years since the X-Prize, and commercial suborbital flights haven’t started yet. The future is behind schedule. So, today is a day to remember but not to celebrate. That will come when the work is done.

Written by Astro1 on June 21st, 2012 , Scaled Composites, Space History

Florida and Puerto Rico are competing with Texas for the site of the new SpaceX launch site, according to the Orlando Sentinel. Texas appears to have the inside track, however, according to a statement by CEO Elon Musk as reported by the Associated Press.

Why is Texas leading the race for the SpaceX facility?

José Pérez-Riera, Puerto Rico’s secretary for economic development and commerce, points out that the island commonwealth is closer to the equator than either Cape Canaveral or Brownsville. That would translate into slightly greater lift capacity for SpaceX rockets. SpaceX might also benefit from lower labor costs and the fact that Puerto Rico residents do not pay US income taxes.

On the other hand, a Puerto Rico launch site would come with some political uncertainty. Puerto Rico’s commonwealth status could change in the future if the island opts for either statehood or independence. Statehood would change the tax situation, but independence could be particularly worrisome. As an independent nation, Puerto Rico would be subject to US export controls, requiring ITAR permits for every rocket and payload.

Florida officials have argued that locating a second SpaceX pad in that state would save money by eliminating redundancy in the SpaceX supply chain. Redundancy, however, may be exactly what SpaceX is seeking. Locating all of its launch sites in one geographic area would leave SpaceX vulnerable to a localized natural disaster. The Florida Space Coast is infamously vulnerable to storm surge. In 2004, Hurricane Frances threatened to wipe out the entire Shuttle infrastructure.

Increasing its presence in Texas would also increase SpaceX’s base of political support. There’s also the matter of proximity to Johnson Space Center and the surrounding manned space community. That may be a small consideration at present, since NASA currently plans to make Kennedy Space Center the lead for commercial crew activities. That, too, is a political consideration that could change in the future, however. With Congressional elections every two years, it behooves SpaceX to keep its options open. A Texas launch site would also be a signal to the Florida delegation that they cannot take SpaceX for granted.

 

Written by Astro1 on June 20th, 2012 , Spaceports, SpaceX Tags:

The Messerschmitt 262 Replica Project has created five close copies of the world’s first jet fighter. We lost track of the project a few years ago. It appears to have turned out well. The Collings Foundation has acquired one of the replicas, which it’s showing at air shows, and you’ll be able to buy flight time from the Foundation in the near future.

We had the opportunity to sit in the (amazingly cramped) cockpit of the Me-262 replica a few years ago, followed by a private demonstration. It is an amazing aircraft.

Back around the turn of the 21st Century, XCOR Aerospace played with the idea of building a replica of the rocket-power Me-163. A German foundation did build an unpowered glider version, though.

Read the rest of this entry »

Written by Astro1 on June 19th, 2012 , Space Exploration (General)

NASA’s Near-Earth Object Observations Program is keeping a close eye on 2011 AG5, an Earth-crossing asteroid that could hit the Earth on February 5, 2040.

2011 AG5 is 140 meters in diameter. In the unlikely event of an impact, it would strike with the force of a 100-megaton bomb. NASA is sufficiently concerned that it held a Potentially Hazardous Asteroid Workshop at NASA Goddard Space Flight Center last month.

The probability of 2011 AG5 hitting Earth is currently estimated at 0.2%, but the estimate is still being refined. The probability will change when the asteroid passes through a gravitational keyhole on a pass by Earth in February 2023.

If 2011 AG5 is on a course toward Earth, further data could raise our certainty to 70%. Such data could be used to plan an intercept mission, which could occur either before or after the 2023 keyhole event.

Unfortunately, it’s currently impossible to observe 2011 AG5 because its relative position is too close to the Sun. It will not be possible for astronomers to observe 2011 AG5 again until fall of 2013.

Observing objects that appear close to the Sun will be one of the key missions for suborbital telescopes, such as the Atsa Suborbital Observatory which is slated to fly on the XCOR Lynx Mark III. The Atsa Observatory won’t be flying in time to help with the 2011 AG5 problem, but it will be valuable for studying similar asteroids in the future.

XCOR Lynx with Atsa Suborbital Observatory space telescope

A robust plan for dealing with potentially hazardous asteroids will require a range of in-space capabilities, from suborbital observatories to deep-space intercept and deflection techniques.

Suborbital spacecraft are being developed in the private sector and do not require government investment – but what about the intercept and deflection problem?

Apollo 9 astronaut Rusty Schweickart, who created the B612 Foundation to develop asteroid-deflection techniques, does not think NASA is doing enough. Schweickart discusses 2011 AG5 and possible deflection techniques in the following video.

Written by Astro1 on June 18th, 2012 , Astronomy, Planetary Defense, XCOR Aerospace

Nanoracks LLC  and the National Center for Earth and Space Science Education have announced a student experiment flight opportunity for April 2013.

This opportunity is part of the Student Spaceflight Experiment Program, which enables educational groups to fly small experiments on the Nanoracks Mini-Laboratory payload carrier. SSEP is primarily geared toward primary and secondary schools (grades 5-12), but it is also open to community colleges, universities, and informational education centers.

The baseline cost for a participating institution is $19,950. For that price, the institution receives access to one Mini-Lab Fluids Mixing Enclosure, a cylindrical tube 6.75 inches long with an outside diameter of 0.5 inches. This tube can be divided into one, two, or three sections containing solids or fluids to be mixed together on orbit.

The program also includes a flight experiment design competition, run by the participating institution in cooperation with the National Center for Earth and Space Science Education, which exposes students to how real science is done.

The National Center for Earth and Space Science Education will help participating institutions find sponsors to cover the cost of the experiment, and has been successful in most cases, but sponsorship is not guaranteed. A funding commitment for the flight is required by September 12, 2012.

SSEP payloads have already flown on the Space Shuttle (STS-134 and STS-135, the final flights of the Endeavour and Atlantis) and on the International Space Station. An SSEP payload containing 12 student experiments was part of of the cargo delivered to the International Space Station by the SpaceX Dragon capsule in May. Another SSEP payload with 12 students is scheduled to be delivered to the ISS on the next Dragon flight in September.

For additional information, click. here.

Written by Astro1 on June 17th, 2012 , Citizen Science (General), Commercial Space (General), Education

Ardusat is a project that will allow Arduino programmers to run their programs on satellite in space without actually having to build a satellite.

The Ardusat team is developing a CubeSat satellite with an Arduino payload. Arduino, for those who don’t know, is a popular open-source micro controller board. In addition to the Arduino board, the satellite will have an assortment of sensors including a camera, GPS, ozone and carbon-dioxide sensors, a geiger counter, thermometer, magnetometer, inertial measurement unit, and vibration, light, and pressure sensors.

When Ardusat is in orbit, programmers will be able to upload code to run on the Arduino board. There’s also an opportunity to propose additional sensors prior to launch.

The Ardusat team has created a Kickstarter project to help fund the project. They’re trying to raise $35,000. To pledge money to the project, go here.

Written by Astro1 on June 17th, 2012 , Electronics, Innovation, Nanosatellites

A homebrew computer hacker named Chris Fenton has built a working 1/10-scale Cray-1A computer replica which is binary-compatible and cycle-accurate to the original.

The project was hard because Chris not only wanted the replica to perform like the original, he wanted it to look like the original. He was also working on a budget and didn’t have many thousands of dollars to throw around. If you just want to run Cray code, there’s a DOS-based Cray emulator you can download.

The irony here is that the Cray was once promoted as “the machine that will change the world” while microcomputers like the Altair 8800 and Apple I were dismissed as toys. Yet, it was the microcomputer that changed the world, and now, the Cray computer has been (quite literally!) reduced to a toy.

Today, the “experts” in Congress tell was that the Space Launch System is the rocket that will save space exploration; suborbital rockets like SpaceShip Two, Lynx, and XAero are toys.

Those who fail to learn the lessons of history can still run for Congress.

Written by Astro1 on June 17th, 2012 , Electronics, Innovation, Space Exploration (General)

By coincidence, the US Air Force X-37B orbital test vehicle has returned to Earth on the same day China launched the first crew to its Tiangong-1 space station.

Expect the news media to make much of both events.

Read the rest of this entry »

Written by Astro1 on June 16th, 2012 , Space Exploration (General)

President Calvin Coolidge is famously reported to have said the business of America is business. That is actually a misquote, but it does sum up the traditional  view of America as an industrial, and industrious, society.

Today, however, politicians seems to have embraced a new view: that the business of America is government. This is not a partisan criticism. No one would deny that President Obama is a  supporter of big government, including President Obama himself. What’s more surprising is how many of his Republican  opponents feel the same way.

An example of this is the recent statement by Representative Frank Wolf (R-VA), chairman of the House Appropriations subcommittee  for Commerce, Justice, and Science, on the future of NASA’s Commercial Crew Program.

Read the rest of this entry »

Written by Astro1 on June 16th, 2012 , Commercial Space (General)

One of the primary goals of Citizens in Space is to promote citizen space exploration. Therefore, it seems appropriate for us to define what we mean by space exploration.

Read the rest of this entry »

Written by Astro1 on June 15th, 2012 , Space Exploration (General)

Citizens in Space will be featured at the Silicon Valley Space Business Roundtable on Thursday, June 21. The theme for the evening is “Citizen Science: Low Risk… High Impact.”

Also participating in the event will be speakers from James Cameron’s DeepSea Challenge project, SETI@home, ClickWorkers, Jellywatch, and Mavericks Rocketry.

The roundtable takes place at TechShop in Menlo Park from 6:00 pm til 9:00. Early-bird registration is $20. More details on the event are available here. Tickets and registration are available here.

[google-map-v3 width=”700″ height=”400″ zoom=”12″ maptype=”roadmap” mapalign=”center” directionhint=”false” language=”default” poweredby=”false” maptypecontrol=”true” pancontrol=”true” zoomcontrol=”true” scalecontrol=”true” streetviewcontrol=”true” scrollwheelcontrol=”false” draggable=”true” tiltfourtyfive=”false” addmarkermashupbubble=”false” addmarkermashupbubble=”false” addmarkerlist=”TechShop, Meno Park, CA{}1-default.png{}TechShop” bubbleautopan=”true” showbike=”false” showtraffic=”false” showpanoramio=”false”]
Written by Astro1 on June 15th, 2012 , Citizens in Space, Events

cowboy, horse, and spaceship

Texas may soon have more spaceports than any other state.

Read the rest of this entry »

Written by Astro1 on June 14th, 2012 , Armadillo Aerospace, Spaceports, SpaceX Tags:

Wired has an article on an Apollo lunar orbit rescue concept from 1965.

The idea was to have a specially outfitted Apollo Command Service Module, with a single pilot, standing by on the launch pad. If something went wrong with the ship in lunar orbit, the rescue ship would be launched.

The problem with the concept is obvious. The crew in lunar orbit would likely run out of oxygen before the rescue ship arrived.  Because of that limitation, as well as the cost, the rescue project was never pursued. Apollo was left with no rescue capability in lunar orbit.

The Orion “Apollo on Steroids” architecture, pursued during the George W. Bush Administration, had the same safety vulnerabilities as Apollo, plus one additional failure mode. Instead of leaving a command module pilot in lunar orbit, the Orion architecture proposed to have all the astronauts descend to the surface, leaving the command module on autopilot for several weeks. At the end of their lunar stay, the astronauts would return to the Orion command service module and ask the computer to “open the pod bay doors,” as Arthur C. Clarke famously put it.

Read the rest of this entry »

Written by Astro1 on June 13th, 2012 , Innovation, Space Exploration (General), Space Medicine and Safety

XCOR Aerospace and Space Expedition Curaçao held a press conference in New York City on June 7 to announce their new marketing arrangement for Lynx flights.

Written by Astro1 on June 13th, 2012 , XCOR Aerospace
maillot de foot de la france boutique maillot de foot paris maillot allemagne pas cher maillot foot usa maillot de foot montpellier maillot allemagne pas cher maillot saint etienne pas cher pantalones cortos pantalones cortos zapatos baratos Adidas venta Sconti camicie e pullover Premier League Maglia Manchester United Maglia Manchester United Maglia Arsenal Maglia Chelsea top to 40% off for soccer jerseys top to 40% off for soccer jerseys top to 40% off for soccer jerseys